Belt guard for sewing machines

ABSTRACT

A belt guard is disclosed for a sewing machine which is adapted to be hinged in a cut-out in a table top through which a drive belt extends upwardly to a belt pulley on the sewing machine main shaft. The belt guard includes a portion fixed to the sewing machine frame and a movable portion pivoted at the top to the fixed portion. The movable belt guard portion extends to the opposite side of the hinge between the sewing machine and the table top where it is formed with a cam surface which slides along the table top when the sewing machine is turned upwardly to influence a separation of the belt guard portions so as to provide access for inspection and replacement of the drive belt.

United States Patent 1191 La Police et al.

[ BELT GUARD FOR SEWING MACHINES [75] Inventors: George D. La Police, Somerville;

Charles R. Odermann, Lake Valhalla, both of NJ.

[73] Assignee: The Singer Company, New York,

UNITED- STATES PATENTS 947,651 l/l910 Schreiber 112/261 2,168,501 8/1939 Stoyanows 112/261 2,790,407 4/1957 Andres 112/261 11] 3,834,335 1451 Sept. 10,1974

Primary Examiner-George H. Krizmanich Attorney, Agent, or Firm-Marshall J. Breen; Chester A. Williams, Jr.; Robert E. Smith [57] ABSTRACT A belt guard is disclosed for a sewing machine which is adapted to be hinged in a cut-out in a table top through which a drive belt extends upwardly to a belt pulley on the sewing machine main shaft. The belt guard includes a portion fixed to the sewing machine frame and a movable portion pivoted at the top to the fixed portion. The movable belt guard portion extends to the opposite side of the hinge between the sewing machine and the table top where it is formed with a cam surface which slides alongthe table top when the sewing machine is turned upwardly to influence a separation of the belt guard portions so as to provide access for inspection and replacement of the drive belt.

3 Claims, 3 Drawing Figures 1 BELT GUARD FOR SEWING MACHINES BACKGROUND OF THE INVENTION Belt guards are known in the prior art which can accommodate movement of the sewing machine about hinges on a table top, but such known belt guards are of complicated construction with exacting dimensional requirements and tolerances or require complicated fastenings which must be adjusted each time the sewing machine is tipped back.

BRIEF SUMMARY OF THE INVENTION It is an object of the present invention to provide a belt guard of simple and inexpensive, construction which can accommodate tipping back of the sewing machine in a hinged mounting on a work table without requiring an adjustment of any fastening means. It is an object to provide a belt guard which will open to expose the belt for inspection or repairs when the sewing machine is tipped up, and which will return to closed belt guarding position when the sewing machine is pivotally returned to operative sewing position on the table top. These objects of the invention are attained by an arrangement of a belt guard including a fixed portion secured to the sewing machine and disposed on the same side of the hinge as is occupied by the sewing machine together with a movable belt guard portion pivotally connected to the fixed belt guard portion and extending to the opposite side of the hinge by which the sewing machine is pivoted to the table top. By this arrangement, when the sewing machine is tipped back, the movable portion of the belt guard will be cammed by a sliding contact with'the table top causing the belt guard portions to swing apart to expose the belt, and the center of gravity of the movable portion of the belt guard is arranged so as to provide a gravitational force returning the belt guard portions into complemental cooperation when the sewing machine is tipped back into operative position.

DESCRIPTION OF THE DRAWINGS With the above and additional objects and advantages in view,as will hereinafter appear, thisinvention is illustrated in the accompanying drawings of a sewing machine in which,

FIG. 1 illustrates an end elevational view of a sewing machine connected hingedly in a cut-out in a table top shown in an operative sewing position with a belt guard of this invention applied thereto, 3

FIG. 2 is an end elevational view of the-sewing machine of FIG. 1 tipped back as for inspection or repair A drive belt 17 is entrained on the belt pulleylS and extends downwardly therefrom through a slot 18 in a table top 19 to a'source of driving power such as a transmitter or the like (not shown).

The sewing machine 11 is supported on the table top 19, and more particularly, is arranged within a cut-out 20 formed on the table top 19 by means of hinge members 21 secured along one edge of the sewing machine work supporting bed 12 and pivotally accommodated in hinge socket members 22 carried in the table top 19 adjacent to the cut-out 20. The sewing machine with a hinged connection to the table top as thus described may be turned up into an inoperative position as shown in FIG. 2 for inspection or repair or may be turned down into an operative sewing position as shown in FIG. 1. The driving belt 17 will occupy any operative taut condition when the sewing machine is turned down into operative sewing position as shown in FIG. 1 and in this position the belt poses a source of danger to the operator which requires a means for shielding and guarding against accidental contact with the operators clothing or the like. When the sewing machine is tipped up as shown in FIG. 2, the-belt 17 will be slackened and will not be effective to drive the sewing machine. In this inoperative condition, guarding from accidental contact with the operator or her clothing is not imperative, and furthermore, when in this inoperative position, it is advantageous for the belt guard to be opened and showing the belt guard of this invention shifted into open position exposing the belt, and

FIG. 3 is a cross sectional view of the belt guard and a fragment of the sewing machine taken substantially along line 3-3 of FIG. 1.3

DESCRIPTION OF THE INVENTION As shown in the drawings, the belt guard of this invention includes afixed portion 30 which includes a supporting limb 31 slotted as at 32 to accommodate fastenings 33 by which the fixed belt guard portion is secured to the sewing machine bracket arm 13. Spaced from the supporting limb 31 of the fixed portion 30 of the belt guard by an edge portion 34 is abelt cover limb 35 which is formed so as to encompass substantially that half of the belt pulley 15 which is diametrically opposite to the edge of the sewing machine work support to which the hinge members 21 are secured. The belt cover'limb 35 of the fixed portion 30 of the belt guard extends downwardly substantially to the level of the sewing machine work supporting bed 12 and is disposed completelyon the same side of the hinge members 21 as is occupied by the sewing machine. With this arrangement, the fixed portion 30 of the belt guard will not in any way interfere when the sewing machine is tipped up about the hinged members 21. l

The belt guard of this invention also includes a movable portion 40 which is formed with limbs 41 and 42 maintained in spaced relation by an edge portion 43.

The limbs 41 and 42 are arranged parallel to the sup-- porting limb 31 and belt cover limb 34, respectively, of

the-fixed portion 30 of the belt guard. The limb 42 of the movable belt guard portion 40 complements the belt cover limb 34 of the fixed portion of the belt guard to provide an exterior cover for the belt when the sewing machine is tipped into operative-position. Themovable portion 40 of .the belt guard is pivotally connected to the fixed portion 30 of the beltguard by a hinge 44 located substantially on the vertical central line of the sewing machine bracket arm vertically above the work supporting bed when the sewing machine is in operative position as shown in FIG. 1. The movable belt guard portion 40 encompasses that portion of the pulley 15 which is not encompassed by the fixed belt guard 3 portion 30 and the spaced limbs 41 and 42 of the movable belt guard portion 40 extend downwardly from the hinge 44 substantially to the levelof the work supporting bed 12 and on the opposite side of the hinge members 21 from that occupied by the sewing machine.

The cantilevered arrangement of the movable portion 40 of the belt guard provides for a location of the center of gravity (indicated at 50) of the movable portion to the right of the hinge 44 between the belt guard portions as shown in the drawings so that the force of gravity continuously acts to close the belt guard portions.

A cam surface 60 is provided on the bottom edge of the movable portion 40 of the belt guard adapted to slide along the table top 19 when the sewing machine is turned about the hinged member 21. Preferably the cam surface 60 includes a slightly curved main portion 61 and a sharply curved nose portion 62 designed to minimize interference between the movable belt guard portion of the table top 19. As the sewing machine is turned up to the position as illustrated in FIG. 2, the Y fixed and movable portions of the belt guard to expose the belt for inspection and replacement. When the sewing machine is again returned to operative position, as

shown in FIG. I,' the movable portion 40 will be returned into closed position in which the limb 42 of the movable portion and the limb 34 of the fixed portion will define a substantial continuous belt cover shrouding the drive belt 17 from contact by the operator.

Having set forth the nature of this invention, what is claimed herein is;

1. In a sewing machine having a work supporting bed hinged along one edge to a table top, a bracket arm rising vertically above said bed, an actuating shaft journaled in said bracket arm, and a belt pulley carried by said actuating shaft and accommodating a drive belt extending from beneath said table top, a belt guard including a portion fixed to said bracket arm and formed with a belt cover arranged in spaced relation to said bracket arm to define a belt accommodating passageway therebetween, the belt cover of said fixed postion of the belt guard being disposed completely on the same side of said hinge as is occupied by the sewing machine and encompassing substantially that half of the belt pulley which is diametrically opposite to the hinged edge of said work supporting bed, and said belt guard including a movable portion formed with a belt cover arranged in spaced relation to said bracket arm to define a belt passageway therebetween and encompassing substantially the other half of said belt pulley, a pivotal connection between said fixed and movable belt guard portions located to the opposite side of said sewing machine belt pulley from said worksupporh'the belt cover of said movable belt guard portion extending from said pivotal connectiondownwar'dly substantially to the level of said work supporting bed and extending to the opposite side of the hinge from that'occupied by said sewing machine.

2. [n a sewing'machine having a work supporting bed hinged along one edge to a table top so that the sewing machine may be turned down into an operative position with the work supporting bed substantially parallel with the table top or may be turned up for inspection or repairwith the work supporting bed substantially perpendicular to the table top, a bracket arm extending from said work supporting bed, an actuating shaft journaled in said bracket arm, and a belt pulley carried by said actuating shaft to accommodate a drive belt extending from beneath said table top', a belt guard including a fixed portion secured relatively to said sewing machine bracket arm and a movable portion pivotaliy connected to said fixed portion, said belt guard portions being formed with complemental belt covers ar ranged in spaced relation to said sewing machine bracket arm to define a closed belt accommodating passageway therebetween when the sewing machine is turned down, and said movable belt guard portion including a cam edge extending on the opposite side of the hinged edge of said work supportingbed from that occupied by said sewing machine for cooperation with said table top to separate said belt guard portions when said sewing machine is turned up.

3. A belt guard for a sewing machine asset forth in claim 2 in which the center of gravity of the movable belt guard portion is located on that side of said pivotal connection between the fixed and movable belt guard portions which is opposite from said fixed belt guard portion so that a force of gravity will automatically return the movable belt guard portion to closed position with respect to the fixed belt guard portion when th sewing machine is turned down. v 

1. In a sewing machine having a work supporting bed hinged along one edge to a table top, a bracket arm rising vertically above said bed, an actuating shaft journaled in said bracket arm, and a belt pulley carried by said actuating shaft and accommodating a drive belt extending from beneath said table top, a belt guard including a portion fixed to said bracket arm and formed with a belt cover arranged in spaced relation to said bracket arm to define a belt accommodating passageway therebetween, the belt cover of said fixed postion of the belt guard being disposed completely on the same side of said hinge as is occupied by the sewing machine and encompassing substantially that half of the belt pulley which is diametrically opposite to the hinged edge of said work supporting bed, and said belt guard including a movable portion formed with a belt cover arranged in spaced relation to said bracket arm to define a belt passageway therebetween and encompassing substantially the other half of said belt pulley, a pivotal connection between said fixed and movable belt guard portions located to the opposite side of said sewing machine belt pulley from said work support, the belt cover of said movable belt guard portion extending from said pivotal connection downwardly substantially to the level of said work supporting bed and extending to the opposite side of the hinge from that occupied by said sewing machine.
 2. In a sewing machine having a work supporting bed hinged along one edge to a table top so that the sewing machine may be turned down into an operative position with the work supporting bed substantially parallel with the table top or may be turned up for inspection or repair with the work supporting bed substantially perpendicular to the table top, a bracket arm extending from said work supporting bed, an actuating shaft journaled in said bracket arm, and a belt pulley carried by said actuating shaft to accommodate a drive belt extending from beneath said table top, a belt guard including a fixed portion secured relatively to said sewing machine bracket arm and a movable portion pivotally connected to said fixed portion, said belt guard portions being formed with complemental belt covers arranged in spaced relation to said sewing machine bracket arm to define a closed belt accommodating passageway therebetween when the sewing machine is turned down, and said movable belt guard portion including a cam edge extending on the opposite side of the hinged edge of said work supporting bed from that occupied by said sewing machine for cooperation with sAid table top to separate said belt guard portions when said sewing machine is turned up.
 3. A belt guard for a sewing machine as set forth in claim 2 in which the center of gravity of the movable belt guard portion is located on that side of said pivotal connection between the fixed and movable belt guard portions which is opposite from said fixed belt guard portion so that a force of gravity will automatically return the movable belt guard portion to closed position with respect to the fixed belt guard portion when the sewing machine is turned down. 